The Absolutely Fabulous star landed in the country last month as part of a six-day tour, three months after she helped win veteran Gurkha soldiers the legal right to remain in Britain.
Lumley was branded a "goddess" by locals and was treated like royalty during her stay, receiving praise from the country's President Ram Baran Yadav.
She says, "I just can't explain how much it meant to me. The trip was immense and overwhelming and the whole thing was so humbling... I thought there would be a few to meet us in Nepal. I was absolutely aghast and overwhelmed by the number of people there."
And the star, whose father was an officer in the 6th Gurkha Rifles, insists the pilgrimage was made even more enjoyable because the residents acknowledged her for the landmark campaigning victory instead of her acting achievements.
She adds, "They saw me as the person from the campaign and the daughter of a Regiment. It's always rather lovely when people see you in a different light, not as old (Abolustely Fabulous character) Patsy... I want everyone to know how beautiful Nepal is. I'd love to go back... but next time to do more looking rather than being looked at."